Okay I'll try to explain this the best I can-- today while putting some finishing touches on MudNurI--- we were getting ready to change the oil sending unit- (it was leaking we suspect)... so we pull off the air cleaner- I hop ontop of the motor, and WHAT do I see? TWO oil sending units, a small one- and a VERY large one. both of them had factory hook-ups.... etc... however there was only 1 oil pressure gauge... so I head down to the local parts store, to get both replaced.... walk in, tell the guy 86 K5, 305- and, WHY is there two of these- he first asks me-- "thats fuel injected?".. NO sir, thats carborated... "does that have a oil pressure light or guage"... guage...hmmmmmmmm flipping through the books etc.. finally tells me its "fuel cut off switch".... "its a heat choke switch" (WTF is that?).... etc... so needless to say- I said "give me both"... and replaced both of them... but my question to you guys- WTF is up with 2 of them? Totally baffled myself, John, and the guy I bought the truck from....?????any idea's? Brandy HELP!!!!! I need 16.5x 12 rims -------please please please!!!!! oh, still LOVING the new dmax as well!